> you project it to face to face situations it would be really rude behavior. Like in a chat room when you ask someone something with an explicit mention of their handle

The difference is that in person you as the asker are more polite about it also. You don't burst into an unrelated meeting just to ask someone a question. Or elbow your way through a group of friends having a conversation just to ask something unrelated.

But in chat rooms (and emails) you do. Easy for folks to get in a situation where dozens of people every day demand their attention and expect a response.